The purpose of the present disclosure is to provide an all-solid lithium ion secondary battery which is excellent in cycle characteristics and which has a negative electrode including, as a negative electrode active material, at least one selected from the group consisting of a metal capable of forming an alloy with Li, an oxide of said metal, and an alloy composed of said metal and Li. The all-solid lithium ion secondary battery is characterized in that the negative electrode contains a negative electrode active material, a conductive material, and a solid electrolyte, wherein the negative electrode active material includes at least one active material selected from the group consisting of a metal capable of forming an alloy with Li, an oxide of said metal, and an alloy composed of said metal and Li, the solid electrolyte is a LiX-Li2S-P2S5-based solid electrolyte (X is at least one halogen selected from the group consisting of F, Cl, Br, and I), and a volume density of the solid electrolyte is 0.3-0.6 g/cm3.